1. Field of the Invention
This invention relates to providing a power source for an inductive loopset. More particularly, this invention relates to providing operating power to an inductive loopset using battery power provided by a wireless phone.
2. Description of Related Art
Telecoil (T-coil) hearing aid users commonly experience interference from the high-frequency electromagnetic signal emitted by wireless phones when the phone is placed in close proximity to the t-coil. The interference—a “buzz” or “hum” in the hearing aid—makes the use of wireless phone handsets difficult. To assist these users, audio induction systems were created. Audio induction systems operate using the principles of electro-magnetics. When an electrical current is amplified and passed through a wire loop, an electromagnetic field is generated around the wire that varies in direct proportion to the amplitude and frequency of the signal. If another wire (or wire loop) is placed in proximity to this field, an identical current will be passed (induced) to the wire. Finally, the current representative of the original audio signal is amplified for hearing.
Personal loopsets were created to apply the audio induction principle to wireless devices so that the wireless phone could be used with t-coil hearing aids. As shown in FIG. 1, the coil 40 of loopset 5 is worn around the user's neck. The coil 40 is coupled to an impedence-matching device 33 inside the housing 30. The impedance-matching device 33 receives a voice signal from the wireless phone 10, transmits the corresponding electromagnetic field to the coil 40, and ultimately to a hearing aid placed in proximity to the coil 40.
Current designs of loopsets use small cell batteries to power the electronics of the loopset. As shown FIG. 2, the battery 34 provides operating power to the loopset 5 when the terminal 41 has been inserted into the jack 42. The insertion of the terminal 41 completes an electrical path, which allows the loopset 5 to produce an induction current.
The current designs have inherent problems that, if removed, would make major strides in the loopset technology. First, in order for the loopset 5 to operate, the terminal 41 must be plugged into the jack 42. Using this approach, a hearing impaired user is almost forced to constantly wear the loopset to hear an incoming call to the wireless phone 10. This means that the coil 40 is constantly emitting an electromagnetic magnetic field if the loopset is being worn and the battery power is constantly being depleted. This leads to inconvenience and a short battery life. Thus, a user is forced to replace the battery often. However, if a user decides to keep the loopset in a pocket or a bag, to conserve battery power, a user must fumble to put the loopset on if a call is received while the loopset is not being worn.
Thus, the inventors have discerned that there is a need to address the above-mentioned problems by providing a loopset that is more user friendly than current configurations and overcomes the problems identified above.